I’m going to install an awning on a wooden facade. The brackets should, of course, be attached to the studs. I have horizontal paneling and can clearly see where the nails are. The studs should be behind these nails. At the hardware store, they said I should use structural screws that are 100 mm long. I tried screwing one in and it doesn’t catch. It feels like it’s too short. I’ve searched all papers/plans but can’t find how the wall is constructed. It’s an "environmental house" from around 2017. The entire wall is 359 mm thick. According to some images online of similar walls, there are other layers before reaching the studs.
How long should the screws be? Is it dangerous to choose too long a screw and puncture some layer, like a vapor barrier?